screen overlay/render issue.

I thought this was only true when playing tf2, it happens on occasions, more so recently. I get a funny red overlay that flickers up and down the screen on my menu's. I checked it in HL2 ep2 and i had the same problem, but not on TFC when i tried a none source powered game. I'm not sure what the implications are though.

I tried taking a screen shot but the image comes out flawless. As if this issue never existed. What i should be viewing.. it's starting to annoy me.

The symptons vary from time to time but here's a list:

A red translucent layer that renders over mostly brown, orange and red textures ingame and on the menu screen. It also flickers but does not render over dark or light pixels.

A red and blue layer are rendered alternatively, flickering between one and the other, on the menu and ingame. The blue i rarely see and doesn't seem to come up ingame, or if it has i didn't notice it over the overpowering red 'glow'.

A green layer that gets rendered partly over the orange stats bar that appears when joining and changing servers/games, no effect ingame or on the menu. Only the orange bar on the stats overlay.

These translucent colours seem to be effected by the colour beneath them, some colours remain as they should be (washed out desaturated colorus) whilst others pick up this red and/or blue translucent layer.

Anyone else know of this problem?

I posted it in tf2 section simply because it was source related, someone can move it to offtopic if it's innapropriately placed. I have no clue as to what causes it, sometimes it's fine, sometimes it is really bad, other times it only effects overlays. It happened earlier and then stopped randomly, only to come back twice as bad a couple seconds later.